Insulated cast concrete wall system and insulation tie

ABSTRACT

Disclosed is a tie for securing insulation to a cast concrete wall comprising: a head; a shaft attached to the head and having a longitudinal axis, the shaft comprising a series of barbs positioned at pre-determined longitudinal positions along the longitudinal axis, each successive barb being rotated about the longitudinal axis by a pre-determined rotational increment from the immediately preceding barb; and, a tip on the shaft. There is also disclosed a system for constructing an insulated concrete wall comprising: a set of concrete forms comprising two opposing partitions set apart a pre-determined distance; a sheet of insulation secured between the partitions adjacent one of the partitions; and, at least one tie consisting essentially of a head, a shaft attached to the head and a pointed or wedge-shaped tip on the shaft, the tie being inserted through the sheet of insulation such that the tip elastically deforms the insulation to permit passage of the shaft through the insulation and a portion of the shaft extends beyond the insulation into a cavity defined within the forms for securing the insulation to the concrete once the concrete has been poured and cured. A method of constructing an insulated cast concrete wall and a process for making an insulation tie are also disclosed. Inserting the tie into the insulation can be done on-site without any prior preparation of the insulation and can be inserted in any desired pattern greatly facilitating the construction of custom cast concrete walls. Insulation of both sides of the concrete wall can be conveniently done without significant additional labor. A veneer may be applied to one or both insulated surfaces of the cast concrete wall by fastening the veneer to the tie.

FIELD OF THE INVENTION

[0001] The present invention relates to a system for constructing aninsulated cast concrete wall and a tie for securing insulation to a castconcrete wall.

DESCRIPTION OF THE PRIOR ART

[0002] Cast concrete walls are typically constructed by pouring concreteinto a set of forms, curing the concrete and removing the forms. Sinceenergy costs have risen dramatically over the past three decades, it hasnow become desirable to insulate cast concrete walls. Typically,insulation has been added to the wall after casting and curing of theconcrete. However, this technique is very labor intensive and suffersfrom a lack of effective methods for securing the insulation to thewall. Other techniques have been developed whereby the insulation isplaced within the set of concrete forms and the concrete poured aroundor beside the insulation. In some variations, the insulation may beoutfitted with ties which help secure the insulation to the curedconcrete. An example of this variation is disclosed in U.S. Pat. No.6,079,176. While such techniques have increased the effectiveness ofsecuring the insulation to the concrete, they have proven to be laborintensive and have increased the amount of insulation handling.Furthermore, insulation must often be outfitted in advance with ties, orprepared in advance to receive ties, thereby decreasing flexibility ofthe system and requiring undesirable off-site handling of theinsulation. In addition, a system such as that disclosed in U.S. Pat.No. 6,079,176 is difficult to adapt for insulating both sides of a castconcrete wall. Thus, there still remains a need for a simple, flexibleand effective method for constructing insulated cast concrete walls.

SUMMARY OF THE INVENTION

[0003] The present invention provides a tie for securing insulation to acast concrete wall comprising: a head; a shaft attached to the head andhaving a longitudinal axis, the shaft comprising a series of barbspositioned at pre-determined longitudinal positions along thelongitudinal axis, each successive barb being rotated about thelongitudinal axis by a predetermined rotational increment from theimmediately preceding barb; and, a tip on the shaft.

[0004] There is also provided a process for producing an insulation tiecomprising providing a mold having a mold cavity having a shapecomplementary to the tie; introducing a plastic into the mold; and,forming the tie.

[0005] There is further provided a system for constructing an insulatedcast concrete wall comprising: a set of concrete forms comprising twoopposing partitions set apart a pre-determined distance; a sheet ofinsulation secured between the partitions adjacent one of thepartitions; and, at least one tie consisting essentially of a head, ashaft attached to the head and a pointed or wedge-shaped tip on theshaft, the tie being inserted through the sheet of insulation such thatthe tip elastically deforms the insulation to permit passage of theshaft through the insulation and a portion of the shaft extends beyondthe insulation into a cavity defined within the forms for securing theinsulation to the concrete once the concrete has been poured and cured.

[0006] There is still further provided a method for constructing aninsulated cast concrete wall comprising the steps of: providing a set ofconcrete forms having opposing partitions set apart a pre-determineddistance; providing at least one tie consisting essentially of a head, ashaft attached to the head and a pointed or wedge-shaped tip on theshaft; inserting the at least one tie through a sheet of insulation suchthat the tip elastically deforms the insulation to permit passage of theshaft through the insulation until a portion of the shaft extends beyondthe insulation; securing the sheet of insulation between the partitionsadjacent one of the partitions such that the portion of the shaftextending beyond the insulation extends into a cavity defined within theforms; and, pouring concrete into the cavity and curing the concrete.

[0007] The tie of the present invention is easy to use and is impaledthrough the sheet of insulation, obviating the need for pre-formingpassages to accommodate the tie. The tie may therefore be insertedthrough the insulation on-site in any desired pattern, providingflexibility during construction. The system and method of the presentinvention use conventional concrete forming techniques to quickly erectan insulated cast concrete wall with minimal labour and withoutre-training of personnel. The ties may be manufactured simply and withlow cost using, for example, plastic injection molding techniques.Veneer can be applied to the insulated surface of the wall by fasteningthe veneer to the ties. Either one or two sides of the wall can bereadily insulated using the system and method of the present invention.This permits application of veneer to both sides of the wall if sodesired.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order that the invention may be more clearly understood,preferred embodiments hereof will now be described in detail by way ofexample, with reference to the accompanying drawings, in which:

[0009]FIG. 1a is a side view of an insulation tie of the presentinvention;

[0010]FIG. 1b is a top view of the insulation tie of the presentinvention;

[0011]FIG. 1c is an end view of the insulation tie of the presentinvention;

[0012]FIG. 2 is a sectional view of a system for constructing aninsulated cast concrete wall; and,

[0013]FIG. 3 is an exploded sectional view of a veneer being attached toan insulated cast concrete wall.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0014] With reference to FIGS. 1a-1 c, an insulation tie of the presentinvention is shown. The insulation tie has a head 1, a shaft 2, and atip 3.

[0015] The head 1 may be of any suitable shape, such as square,rectangular, or preferably round, and has a thickness of preferablyabout 1 to 5 mm, more preferably about 2 mm. The thickness is chosen topermit a fastener, for example a screw or nail, to be anchored into thehead 1 for attachment of a veneer to the insulation tie in a manner thatwill be more thoroughly described hereinafter. The head 1 may have adiameter of preferably about 5 to 10 times the width of the shaft 2,more preferably about 7 times the width of the shaft.

[0016] The shaft 2 may be of any suitable polygonal cross-section, suchas round or rectangular, but is preferably square. Preferably, the widthof the shaft 2 is uniform and about ¼ the thickness of the sheet ofinsulation to be retained. The shaft 2 is preferably attached to thehead 1 at substantially the center thereof. The shaft 2 is substantiallyperpendicular to the head 1 and the longitudinal axis of the shaftdefines the longitudinal axis of the insulation tie. The length of theshaft 2 is preferably about 4 to 6 times the thickness of the sheet ofinsulation to be retained. Gussets 4 are attached to both the shaft 2and the head 1 to strengthen the tie and help maintain the alignment ofthe shaft with respect to the head.

[0017] The shaft 2 has a tip 3 at the end of the shaft opposite the head1. The tip 3 is narrower than the shaft and may be rounded, pointed, orwedge-shaped, preferably pointed or wedge-shaped. When the insulationtie is inserted through a sheet of insulation by impalement of the tie,the tip 3 elastically deforms the insulation to permit passage of theshaft 2 through the sheet. The width of the shaft 2 is chosen so that itmay pass through the sheet in co-operation with the tip 3 withoutforming a hole. The insulation thereby conforms to the outside surfaceof the shaft 2 when inserted through the sheet. This allows the tie tofit snugly within the sheet and obviates the need for pre-forming holesto permit passage of the shaft 2, saving labour and allowing theposition of the tie to be determined on-site.

[0018] The shaft 2 comprises a series of barbs 5 positioned atpre-determined longitudinal positions along the longitudinal axis of theshaft. The increment in longitudinal position between successive barbs 5in the series need not be uniform. Each barb 5 may be of any suitableshape provided that a portion of each barb extends transversely from theshaft. Preferably, the barbs 5 extend a uniform pre-determined distancefrom the shaft. Preferably, the barbs 5 have a triangular cross-sectionand are wedge shaped. Each successive barb 5 in the series is rotatedabout the shaft 2 a pre-determined rotational increment from theimmediately preceding barb. The rotational increment need not beuniform; however, preferably each successive rotational increment is 90degrees. This arrangement helps ensure that a hole is not formed whenthe tie is inserted through the sheet of insulation. The series of barbs5 further comprises counterpart barbs 6 juxtaposed 180 degrees about thelongitudinal axis. Each barb 5 in the series therefore has a counterpartbarb 6 at the same longitudinal position, but on the opposite side ofthe shaft 2.

[0019] The longitudinal position of at least one of the barbs 5 in theseries, preferably the first barb 7, is pre-determined according to thethickness of the insulation to be retained. Preferably, the first barb 7has a face that is substantially perpendicular to the longitudinal axis.The longitudinal position of the first barb 7 is pre-determined so thatits face and that of its counterpart 8 rests against the surface of thesheet of insulation when the tie is fully inserted through the sheet.The longitudinal position of the next barb in the series may bepre-determined to accommodate a different thickness of insulation.

[0020] The tie may be manufactured of any suitable material thatprovides sufficient structural strength to allow the tie to be impaledthrough the sheet of insulation while allowing easy attachment of afastener to the head 1. The head 1 and shaft 2 may be made fromdifferent materials. The preferred material of manufacture is a plasticand preferably the tie is manufactured as a single piece using a mold.

[0021] The preferred process for producing the insulation tie comprisesproviding a mold having a mold cavity having a shape complementary tothe tie. The plastic may then be introduced into the mold by suitablemeans, for example injected into the mold using a piston or pump. Theplastic is then solidified to form the tie using conditions suitable forthe plastic chosen; for example, temperature and/or pressure conditionsmay be selected according to the type of plastic that allow the plasticto be introduced into the mold as a liquid and then changed to solidifythe plastic. Suitable plastics include but are not limited tothermoplastics, for example polyolefins, such as polyethylene orpolypropylene.

[0022] With reference to FIG. 2, a method for constructing an insulatedcast concrete wall comprises a set of concrete forms comprising twoopposing partitions 9, 10 set apart a pre-determined distance. Theconcrete forms are of the conventional type, typically rectangular andmade of wood. The forms are generally transported to the site and setupin a manner that is known to those skilled in the art using a boom truckor similar means to place the forms on top of a pre-prepared concretefooting 11. A set of concrete forms comprising a series of opposingpartitions 9, 10 may be assembled with the edges of the partitions 9, 10adjacent to one another. The opposing partitions 9, 10 are set apart adistance corresponding to the thickness of the concrete wall to be castplus the thickness of insulation. The opposing partitions 9, 10 may beheld together by any suitable connecting means, for example connectingrods 12, that span the intervening space between the partitions. Each ofthe connecting rods 12 is attached at one end to one of the partitions 9and at the other end to the opposing partition 10. The connecting rods12 prevent the partitions 9, 10 from separating during the subsequentpouring of concrete.

[0023] A tie having a head 1, a shaft 2 attached to the head, and apointed or wedge-shaped tip 3 on the shaft is inserted through a sheetof insulation 13. The tip 3 elastically deforms the insulation 13 topermit passage of the shaft 2 through the insulation as previouslydescribed. When the tie is inserted through the sheet of insulation, aportion of the shaft 2 extends beyond the insulation. The tie may beinserted on site by any suitable means, such as impact with a hammer orsimply by applying pressure to the head 1 of the tie by hand. When thetie is fully inserted, the head 1 is directly adjacent a surface of thesheet of insulation 13; alternatively, the tie may be partially insertedand the insertion completed during the subsequent pouring of concrete. Aplurality of ties may be inserted in any desired pattern at any desiredspacing in each sheet of insulation 13.

[0024] After insertion of at least one tie, the sheet of insulation 13is placed between the forms and secured adjacent the inside surface ofone of the partitions 9. The sheet 13 is generally rectangular andsimilar in size to the partition 9 so that the sheet may preferably besecured by wedging it between the connecting rods 12. Optionally, thesheet 13 may be held in place by a clip (not shown) placed over theconnecting rod 12 adjacent the inside surface of the sheet. A singlesheet 13 may be inserted against one of the partitions 9 to insulate onesurface of the wall or, optionally, a second sheet 14 may be insertedagainst the opposing partition 10 to insulate both surfaces of the wall,as shown in outline in FIG. 2.

[0025] The portion of the shaft 2 extending beyond the insulation 13extends into a cavity 15 defined within the forms. The cavity 15 isdefined by the interior opposing surfaces of the sheet 13 and either thesheet 14 or the partition 10, depending, respectively, on whether bothsurfaces or a single surface of the wall is being insulated. The tip 3of the tie may terminate within the cavity 15 to prevent the tip fromprotruding through the wall. This is especially desirable when bothsurfaces of the wall are insulated. Within the cavity 15, steel re-bar16 may be added to strengthen the wall. The re-bar 16 is generallycomprised of cylindrical corrugated steel strips horizontally orientedwithin the cavity 15.

[0026] To form the wall, concrete is poured into the cavity 15 andcured. The concrete presses the insulation 13 firmly against thepartition 9, completing the insertion of any partially inserted ties andcounter-sinking the head 1 into the insulation until it is flush withthe surface of the sheet. The concrete surrounds the re-bar 16 and theportion of the shaft 2 extending into the cavity 15. Upon curing, theconcrete sets around the shaft 2 and the series of barbs 5 anchor thetie within the wall, thereby holding the insulation 13 securely inplace. After the concrete has set, the forms may be removed and re-used.

[0027] With reference to FIG. 3, after removal of the forms a veneer 17may be applied to the insulated surface of the wall 18. A wall that isinsulated on one side only is shown in exploded view in FIG. 3, althoughthe same principles apply if both sides are insulated. A veneer 17 maybe placed adjacent the insulated surface 18 and fastened to the tie, forexample by screwing into the head 1. The pattern and spacing of the tiesare preferably uniform to facilitate attachment of the veneer 17. Thescrew 19 is fastened directly to the tie without the need for apre-formed hole and the tie is not required to spread upon insertion ofthe screw. For the application of certain types of veneer 17, it may bedesirable to apply strapping, for example strips of wood (not shown), tothe surface of the sheet of insulation 18 before application of theveneer 17. The strapping is preferably fastened to the tie prior tofastening the veneer 17 to the strapping. The strapping is typicallyoriented horizontally with a single piece of strapping spanning severalties. For interior surfaces, the veneer 17 may include, for example,drywall, paneling, or plywood. For exterior surfaces, the veneer 17 mayinclude, for example, vinyl or aluminum siding, corrugated steel and mayfurther include bricks or stone masonry. The latter may require the useof specialized fasteners in addition to screws 19.

[0028] Other advantages which are obvious and which are inherent to thestructure will be evident to one skilled in the art.

[0029] It will be understood that certain features and sub-combinationsare of utility and may be employed without reference to other featuresand sub-combinations. This is contemplated by and is within the scope ofthe claims.

[0030] Since many possible embodiments may be made of the inventionwithout departing from the scope thereof, it is to be understood thatall matter herein set forth or shown in the accompanying drawings is tobe interpreted as illustrative and not in a limiting sense.

1. A tie for securing insulation to a cast concrete wall comprising: (a)a head; (b) a shaft attached to the head and having a longitudinal axis,the shaft comprising a series of barbs positioned at pre-determinedlongitudinal positions along the longitudinal axis, each successive barbbeing rotated about the longitudinal axis by a predetermined rotationalincrement from the immediately preceding barb; and, (c) a tip on theshaft.
 2. The tie according to claim 1, wherein the tip is pointed orwedge-shaped.
 3. The tie according to claim 2, wherein each successiverotational increment is 90 degrees.
 4. The tie according to claim 3,wherein the shaft is of uniform thickness.
 5. The tie according to claim4 wherein the barbs are triangular in cross-section.
 6. The tieaccording to claim 5, wherein each barb extends a pre-determined uniformdistance transversely from the longitudinal axis.
 7. The tie accordingto claim 6, wherein at least one of the pre-determined longitudinalpositions is pre-determined according to insulation thickness.
 8. Thetie according to claim 7, wherein the series of barbs further comprisescounterpart barbs juxtaposed 180 degrees about the longitudinal axis. 9.A process for producing an insulation tie comprising: (a) providing amold having a mold cavity having a shape complementary to the tie asdefined in claim 1; (b) introducing a plastic into the mold; and, (c)forming the tie.
 10. A process for producing an insulation tiecomprising: (a) providing a mold having a mold cavity having a shapecomplementary to the tie as defined in claim 8; (b) introducing aplastic into the mold; and, (c) forming the tie.
 11. A system forconstructing an insulated cast concrete wall comprising: (a) a set ofconcrete forms comprising two opposing partitions set apart apre-determined distance; (b) a sheet of insulation secured between thepartitions adjacent one of the partitions; and, (c) at least one tieconsisting essentially of a head, a shaft attached to the head and apointed or wedge-shaped tip on the shaft, the tie being inserted throughthe sheet of insulation such that the tip elastically deforms theinsulation to permit passage of the shaft through the insulation and aportion of the shaft extends beyond the insulation into a cavity definedwithin the forms for securing the insulation to the concrete once theconcrete has been poured and cured.
 12. The system according to claim11, wherein the shaft has a longitudinal axis and comprises a series ofbarbs positioned at pre-determined longitudinal positions along thelongitudinal axis, each successive barb being rotated about thelongitudinal axis by a predetermined rotational increment from theimmediately preceding barb.
 13. The system according to claim 12,wherein the tip of the tie inserted through the sheet of insulationterminates within the cavity.
 14. The system according to claim 13,wherein the partitions are secured together by connecting rods betweenwhich the sheets of insulation are wedged to secure the insulationbetween the partitions before the concrete is poured.
 15. The systemaccording to claim 14, wherein the pre-determined rotational incrementis 90 degrees, the shaft is of uniform thickness, the series of barbsfurther comprises counterpart barbs juxtaposed 180 degrees about thelongitudinal axis, the barbs are triangular in cross-section and extenda pre-determined uniform distance transversely from the longitudinalaxis, and at least one of the pre-determined longitudinal positions ispre-determined according to insulation thickness.
 16. The systemaccording to claim 15, wherein a sheet of insulation is secured adjacenteach of the partitions between the partitions and each sheet ofinsulation is provided with at least one tie inserted through the sheet.17. A method for constructing an insulated cast concrete wall comprisingthe steps of: (a) providing a set of concrete forms having opposingpartitions set apart a pre-determined distance; (b) providing at leastone tie consisting essentially of a head, a shaft attached to the headand a pointed or wedge-shaped tip on the shaft; (c) inserting at leastone tie provided in step (b) through a sheet of insulation such that thetip elastically deforms the insulation to permit passage of the shaftthrough the insulation until a portion of the shaft extends beyond theinsulation; (d) securing the sheet of insulation between the partitionsadjacent one of the partitions such that the portion of the shaftextending beyond the insulation extends into a cavity defined within theforms; and, (e) pouring concrete into the cavity and curing theconcrete.
 18. The method according to claim 17, wherein the shaft has alongitudinal axis and comprises a series of barbs positioned atpre-determined longitudinal positions along the longitudinal axis, eachsuccessive barb being rotated about the longitudinal axis by apre-determined rotational increment from the immediately preceding barb.19. The method according to claim 18, wherein the tip of the tieinserted through the sheet of insulation terminates within the cavity.20. The method according to claim 19, wherein the partitions are securedtogether by connecting rods between which the sheets of insulation arewedged to secure the insulation between the partitions before theconcrete is poured.
 21. The method according to claim 20, wherein thepre-determined rotational increment is 90 degrees, the shaft is ofuniform thickness, the series of barbs further comprises counterpartbarbs juxtaposed 180 degrees about the longitudinal axis, the barbs aretriangular in cross-section and extend a pre-determined uniform distancetransversely from the longitudinal axis, and at least one of thepre-determined longitudinal positions is pre-determined according toinsulation thickness.
 22. The method according to claim 21, wherein asheet of insulation is secured adjacent each of the partitions betweenthe partitions and each sheet of insulation is provided with at leastone tie inserted through the sheet.
 23. The method according to claim22, further comprising removing the forms and attaching a veneer to thehead of at least one of the ties of the insulated cast concrete wall.